A semi-active control magnetorheological elastomer damping device and control method suitable for a fan tower

Abstract

This invention discloses a semi-active control omnidirectional magnetorheological elastomer (MLE) vibration damping device and control method suitable for wind turbine towers, comprising an electric drive turntable module, a MLE vibration damping module, and a pressure-magnetic synergistic stabilization module. The electric drive turntable module uses a pressure sensor ring to identify wind direction, driving the turntable to align the vibration damping module's vibration direction with the wind direction, and periodically oscillating near the prevailing wind direction to cope with turbulence. The MLE vibration damping module achieves synchronous movement of multiple sets of MLEs through a linkage mechanism, using electromagnetic fields to adjust stiffness. The pressure-magnetic synergistic stabilization module senses upward force through a pressure sensor and generates a balancing magnetic force to ensure stable operation. This device employs a dual-variable intelligent control system combining the variable stiffness and damping characteristics of the MLE with rod adjustment, optimizing rod states and unified current in real time based on spectrum analysis to achieve wide-bandwidth, precise, and efficient semi-active vibration damping, effectively improving the vibration resistance of wind turbine towers.

Description

Technical Field

[0001] This invention relates to the field of wind turbine structure vibration control, specifically to a semi-active control magnetorheological elastomer vibration reduction device suitable for wind turbine towers. Background Technology

[0002] Currently, vibration reduction in wind turbine towers mainly relies on semi-active control technologies such as magnetorheological tuned mass dampers (MR-TMD), with magnetorheological fluid (MRF) as the core material. However, issues such as particle settling and aging exist. Magnetorheological elastomers (MREs) are gradually emerging as an upgrade direction. By 2025, the industry will be in a critical period of transitioning from technology verification to engineering demonstration. Companies such as Goldwind have already piloted related solutions in offshore wind farms. At the same time, new devices such as MRE-PTMD are beginning to be optimized for broadband adaptability, but the core bottlenecks have not yet been resolved.

[0003] Existing technologies have several limitations: insufficient frequency domain adaptability, with most devices unable to cover the main vibration frequency band of wind turbines in the 5-30Hz range, and vibration reduction rates mostly below 60%; remote / offshore wind farms lack stable power supplies, and existing devices rely on external power supplies, resulting in high operation and maintenance costs; most are unidirectional controls, unable to cope with the combined vibration of lateral wind loads and longitudinal excitations; magnetorheological fluids are prone to leakage, and their performance degrades at high and low temperatures, with device lifespan generally less than 5 years, far below the 20-year design life of wind turbines.

[0004] A search revealed a Chinese patent with publication number CN110409901B, which describes a magnetorheological elastomer damper as a variable stiffness and variable damping composite damper for vertical vibration reduction. This damper effectively integrates the variable stiffness of magnetorheological elastomers with the variable damping technology of eddy currents. It can change the stiffness by adjusting the excitation coil current to match the main structure frequency, and change the damping magnitude by adjusting the electromagnet magnetic field. During strong vibrations, it can enhance energy dissipation and limit resonance amplitude with the help of the eddy current damping device. Simultaneously, the stable component assembly ensures vibration reduction stability and adapts to different vibration intensity scenarios. However, relying solely on the stiffness and damping adjustment of a single device, it is slightly insufficient in terms of wide-frequency control and cannot cope with vibrations from all directions.

[0005] A search revealed a Chinese patent with publication number CN116696978A, which describes a vibration reduction device for a floating offshore wind turbine based on a magnetorheological damper. This device, installed at multiple locations on the upper, middle, and lower parts of the tower, can target the area of ​​maximum amplitude vibration, extending the vibration period and increasing the damping ratio. The magnetorheological damper has a simple structure, is lightweight, and offers continuous damping adjustment, effectively dissipating external load energy and providing good control over the wind turbine's anti-overturning effect. However, its dispersed installation locations lead to high overall layout complexity, and the device consumes a significant amount of power, hindering energy conservation and emission reduction. Furthermore, compared to magnetorheological elastomer dampers, the magnetorheological damper has a smaller controllable frequency range.

[0006] Therefore, there is a need for a magnetorheological elastomer vibration damping device that can cope with vibrations from all directions and has a dual-variable intelligent control system with adjustable magnetorheological elastomer stiffness and adjustable telescopic rods. Summary of the Invention

[0007] This invention addresses key industry pain points by achieving: wide-band adjustment characteristics enabling continuously adjustable stiffness from 0.5 to 2.0 MPa, precisely covering the 5-30 Hz frequency band, with a vibration reduction rate exceeding 80%, more than 30% higher than traditional devices; a self-powered design achieving zero energy consumption, avoiding the wiring costs (approximately 100,000 RMB per unit) and power outage risks in remote wind farms; a cross-shaped layout overcoming the limitations of unidirectional control, simultaneously suppressing multi-directional composite vibrations; and a magnetorheological elastomer material with no leakage risks, a temperature range of -30℃ to 80℃ suitable for extreme environments, and an 8-year lifespan more than 1.6 times that of existing devices.

[0008] The present invention proposes a semi-active control magnetorheological elastomer vibration reduction device for wind turbine towers, and the technical solution adopted is as follows.

[0009] A semi-active control magnetorheological elastomer vibration damping device suitable for wind turbine towers includes an electric drive turntable module (1), a magnetorheological elastomer vibration damping module (2), and a pressure-magnetic force coordinated stabilization module (3).

[0010] The function of the electric drive turntable module (1) is to make the vibration direction of the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration damping module (2) generally consistent with the external wind direction; the electric drive turntable module (1) includes a pressure sensor ring (28), an electric drive turntable (6) and a force transmission block (5), wherein the pressure sensor ring (28) is installed on the outside of the wind turbine tower; the force transmission block (5) is symmetrically arranged above the electric drive turntable (6);

[0011] Multiple magnetorheological elastomer vibration damping modules (2) are symmetrically distributed and connected below the electric drive turntable (6). The magnetorheological elastomer vibration damping modules (2) are used to achieve the vibration damping effect of the wind turbine tower. The magnetorheological elastomer vibration damping module (2) includes a magnetorheological elastomer (14), a bearing (8), a homogeneous light rod (9), an electromagnetic plate (12), a coil (11) wound on the electromagnetic plate (12), a reset spring (13) sleeved at both horizontal ends of each magnetorheological elastomer (14), an upper telescopic rod (15), a lower telescopic rod (16), a linkage mechanism (10), and a retractable rod. The retractable rod base (17) is provided with a bearing (8) located at the top of the magnetorheological elastomer damping module (2) and connected below a uniform light rod (9). The uniform light rod (9) is connected below a plurality of upper retractable rods (15) via a linkage mechanism (10). The lower ends of the plurality of upper retractable rods (15) pass through an electromagnetic plate (12) and are correspondingly inserted into the upper grooves on the top surfaces of the plurality of magnetorheological elastomers (14). The lower retractable rod (16) connected to the retractable rod base (17) via the linkage mechanism (10) is inserted from below into the lower grooves on the bottom surfaces of the plurality of magnetorheological elastomers (14).

[0012] A magnetic field shielding protective layer (18) and a magnet block (19) are arranged sequentially on the lower part of the outside of the magnetorheological elastomer vibration damping module (2).

[0013] The pressure-magnetic synergistic stabilization module (3) includes a controllable magnetic initiation device (20), a pressure sensor (4), and a control module (21). The pressure sensor (4) is located at the inner top of the vibration damping device and contacts the inner top of the wind turbine tower, and can sense the upward force generated by the upward movement of the vibration damping device. The controllable magnetic initiation device (20) is located below the magnetorheological elastomer vibration damping module (2), and can generate a magnetic force that balances the upward force. The control module (21) is used to control the operation of each component of the vibration damping device.

[0014] Preferably, the control method of the electric drive turntable module (1) is as follows: the electric drive turntable (6) is connected to the magnetorheological elastomer vibration damping module (2) below through symmetrically distributed rigid rods (7); the control module (21) controls the rotation of the electric drive turntable (6) in response to the measurement data of the pressure sensor ring (28);

[0015] In an environment with a specific wind direction, the pressure sensor ring (28) identifies the specific wind direction outside the wind turbine tower and transmits the wind direction identification result to the control module (21). The control module (21) manipulates the electric drive turntable (6) according to the specific wind direction to drive the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration reduction module (2) below it to vibrate. The vibration of the wind turbine tower under the specific wind direction will drive the magnetorheological elastomer (14) to undergo shearing motion and generate shearing force. Under the combined action of the electric drive turntable (6) and the swing of the wind turbine tower, the magnetorheological elastomer (14) generates a shearing force opposite to the external wind direction, which cancels out the external wind force, thereby achieving the best vibration reduction effect.

[0016] When there is no specific wind direction, the control module (21) manipulates the electric drive turntable (6) to rotate slowly at a uniform speed, which drives the magnetorheological elastomer vibration reduction module (2) below to rotate synchronously, so that the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration reduction module (2) generates shear force opposite to the direction of each small vibration of the wind turbine tower, thereby reducing the effect of each small vibration of the wind turbine tower.

[0017] Preferably, the core magnetorheological elastomer (14) inside the magnetorheological elastomer vibration damping module (2) is based on silicone rubber and contains carbonyl iron powder with high magnetic permeability. When no magnetic field is applied, the iron powder is randomly distributed and the magnetorheological elastomer is in a flexible state, which can deform freely with vibration.

[0018] Preferably, when the coil (11) on the electromagnetic plate (12) inside the magnetorheological elastomer damping module (2) is energized, a controllable magnetic field is generated. Under the action of the magnetic field, the iron powder in the magnetorheological elastomer (14) is arranged into a chain structure along the direction of the magnetic field, so that the elastic modulus of the magnetorheological elastomer is synchronously increased and the change is continuous and reversible, thereby realizing wideband adjustment.

[0019] The reset spring (13) inside the magnetorheological elastomer vibration damping module (2) provides initial support for the magnetorheological elastomer (14) on the one hand, and helps the magnetorheological elastomer (14) to quickly reset after vibration, avoiding residual deformation. At the same time, the elastic force of the spring and the adjustable stiffness of the magnetorheological elastomer (14) under the magnetic field are superimposed to form a dual vibration damping structure of "basic buffer + dynamic adjustment".

[0020] Preferably, the upper telescopic rod (15) and the lower telescopic rod (16) inside the magnetorheological elastomer vibration damping module (2) are respectively placed in the upper and lower grooves of the magnetorheological elastomer (14), and any set of upper and lower telescopic rods adopts a simultaneous control scheme; the lower telescopic rod (16) plays the role of fixing the magnetorheological elastomer (14); the upper telescopic rod (15) plays the role of driving each magnetorheological elastomer (14) to move synchronously; the specific control scheme is that when the upper telescopic rod (15) leaves the upper groove, the lower telescopic rod (16) is inserted into the lower groove, thereby fixing the magnetorheological elastomer (14); when the lower telescopic rod (16) leaves the lower groove, the upper telescopic rod (15) is inserted into the upper groove, thereby driving each magnetorheological elastomer (14) to participate in vibration.

[0021] Preferably, the upper telescopic rod (15) and the lower telescopic rod (16) of the magnetorheological elastomer vibration damping module (2) are connected by a linkage mechanism (10) to achieve synchronous movement; the linkage mechanism (10) is equipped with a servo electric cylinder (25), and the rod position encoder is built into the servo electric cylinder (25); the servo electric cylinder (25) can be controlled by the control module (21) to form a dual control of the stiffness adjustment of the magnetorheological elastomer (14) and the telescopic rod adjustment, so as to realize the precise wideband adjustment of the magnetorheological elastomer (14); the telescopic rod includes an upper telescopic rod (15) and a lower telescopic rod (16).

[0022] Preferably, a displacement sensor (22) and a velocity sensor (23) are provided on both sides of the magnetorheological elastomer (14), an acceleration sensor (24) is provided on the top of the wind turbine tower, and a Hall current sensor (26) and a temperature sensor (27) are provided near the coil (11); the displacement sensor (22), velocity sensor (23), acceleration sensor (24), servo motor (24), Hall current sensor (26) and temperature sensor (27) are all electrically connected to the control module (21).

[0023] Preferably, the application scenario and working mode of the pressure-magnetic synergistic stabilization module (3) are as follows: When the electric drive turntable (6) drives the magnetorheological elastomer vibration damping module (2) below to rotate, it will generate an upward force. The force transmission block (5) on the electric drive turntable (6) can transmit the generated upward force to the pressure sensor (4) above the tower. After being subjected to force, the pressure sensor (4) will transmit the pressure magnitude signal to the control module (21). The control module (21) controls the controllable magnetic force initiation device (20) below the magnetorheological elastomer vibration damping module (2) to generate a corresponding magnetic force, which is transmitted to the upper device through the magnet block (19) below the magnetorheological elastomer vibration damping module (2) to make it operate safely and stably. In order to prevent the controllable magnetic force initiation device (20) from affecting the magnetic field in the magnetorheological elastomer vibration damping module (2), a magnetic field shielding protection layer (18) is set between the magnetorheological elastomer vibration damping module (2) and the magnet block (19).

[0024] The present invention also provides a control method for wind turbine tower vibration reduction using a semi-active control magnetorheological elastomer vibration reduction device suitable for wind turbine towers, wherein the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration reduction module (2) is subjected to dual control of stiffness adjustment and telescopic rod adjustment, including the following steps, wherein the telescopic rods include an upper telescopic rod (15) and a lower telescopic rod (16):

[0025] Step 1: Vibration sensing and spectrum analysis. The real-time FFT algorithm is used to collect the tower vibration acceleration time domain signal through the accelerometer (24) at the rated sampling frequency. After windowing filtering preprocessing, the FFT is converted to the frequency domain to obtain the complex spectrum, and the power spectral density is calculated. The frequency corresponding to the maximum power spectral density in the range of 0.2-5.0Hz is extracted as the dominant vibration frequency. The spectrum is divided into three frequency bands to calculate the vibration energy.

[0026] Step 2: Member state decision and member length optimization of the telescopic member. Based on the frequency matching heuristic rule and the sequential quadratic programming (SQP) algorithm, the system calculates the equivalent natural frequency f of each magnetorheological elastic body (14). n,i ; Calculate the natural frequency f n,i With the current dominant vibration frequency f d deviation The unit with the smallest deviation is activated first; the optimal rod length is determined by a weighted combination of minimizing the sum of squares of frequency matching deviation and the sum of squares of rod movement amplitude. The optimization process is constrained by the mechanical stroke of the telescopic rod.

[0027] Step 3: Unified Current Cooperative Optimization, using multi-objective grid search and least squares fitting to optimize the unified coil current I. opt Minimize the difference between the actual damping force and the desired force, as well as the energy consumption I. 2R, where R is the coil resistance; the output force F of each magnetorheological elastic body (14) is calculated. i actual By adjusting the multi-objective weighting coefficients α and β, a trade-off is struck between vibration reduction effect and energy consumption, and the globally optimal damping force is output.

[0028] Step 4: The control module (21) performs precise tracking control, which includes two parallel closed loops: the position of the lever adopts a PID position servo algorithm; the control module (21) receives the target lever length L. i target and the actual rod length L fed back by the encoder. i target (t) Comparison yields the position tracking error e i (t); Output control signal u to drive the servo electric cylinder i (t), ensuring precise movement of the linkages and compliance with mechanical interlocking logic;

[0029] The current control employs a PWM closed-loop regulation algorithm to optimize the target current I. opt To set the value, the actual current I in the coil is measured in real time using a Hall current sensor (26). actual By adjusting the duty cycle of the pulse width modulation signal, rapid and error-free tracking of the coil current is achieved, and the required magnetic field strength is accurately generated.

[0030] Step 5: Safety monitoring and parameter self-learning, multi-threshold graded monitoring of shear strain, coil temperature, tracking error, etc., derating or shutting down when exceeding limits; using recursive least squares to optimize control parameters online, and assessing the vibration reduction efficiency to adapt to changes in working conditions and component aging.

[0031] The present invention also provides the application of the above-mentioned semi-active control magnetorheological elastomer vibration reduction device or the above-mentioned control method for wind turbine tower vibration reduction.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] 1. The electric drive turntable works in conjunction with the pressure sensor ring to combine environmental perception with active execution, solving the problem of "directional mismatch" in traditional wind turbine tower vibration reduction devices when facing changing wind and turbulence, and providing a precise, fast and stable mechanical execution foundation for the entire semi-active control system.

[0034] 2. The device employs a dual-variable control strategy combining "magnetorheological elastomer stiffness adjustment" and "extendable rod length adjustment," forming a dual vibration reduction structure of "basic buffer + dynamic adjustment." Through real-time vibration sensing, spectrum analysis, rod state optimization, and current-coordinated optimization, the system can achieve wide-frequency precise adjustment within the range of 0.5–5.0Hz, adapting to the multi-frequency vibration requirements of the wind turbine throughout its startup, operation, and shutdown processes.

[0035] 3. The device is equipped with a pressure-magnetic coordinated stabilization module. Through the linkage of the force transmission block, pressure sensor, and controllable magnetic induction device, it compensates in real time for the upward force generated by the movement of the vibration reduction module, ensuring that the device is always in a safe and stable working state. At the same time, the system has built-in multi-threshold safety monitoring and recursive least squares (RLS) adaptive learning algorithm, which can evaluate the vibration reduction effect online and adaptively adjust the control parameters to adapt to the changes in operating conditions and component aging during long-term operation of the wind turbine, significantly improving the durability and reliability of the device. Attached Figure Description

[0036] Figure 1 A 3D view showing the location of each module of the vibration damping device inside the wind turbine tower;

[0037] Figure 2 A plan view showing the locations of each module of the vibration damping device inside the wind turbine tower;

[0038] Figure 3 A detailed 3D view of the internal structure of the magnetorheological elastomer vibration damping module;

[0039] Figure 4 A side view showing the detailed internal structure of the magnetorheological elastomer vibration damping module;

[0040] Figure 5 A front view showing the detailed internal structure of the magnetorheological elastomer vibration damping module;

[0041] In the diagram: 1-Electric drive turntable module; 2-Magnetorheological elastomer vibration damping module; 3-Pressure-magnetic force coordinated stabilization module; 4-Pressure sensor; 5-Force transmission block; 6-Electric drive brick disc; 7-Rigid rod; 8-Bearing; 9-Homogeneous light rod; 10-Linkage mechanism; 11-Coil; 12-Electromagnetic plate; 13-Reset spring; 14-Magnetorheological elastomer; 15-Upper telescopic rod; 16-Lower telescopic rod; 17-Telescopic rod base; 18-Magnetic field shielding protective layer; 19-Magnetic block; 20-Controllable magnetic force initiation device; 21-Control module; 22-Displacement sensor; 23-Velocity sensor; 24-Acceleration sensor; 25-Servo electric cylinder; 26-Hall current sensor; 27-Temperature sensor; 28-Pressure sensor ring. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments. The following embodiments provide specific structures and dimensional standards, which will help those skilled in the art to further understand the specific structure of the present invention. Without departing from the basic structure of the present invention, appropriate adjustments can be made to the dimensions of the present invention, all of which fall within the protection scope of the present invention.

[0043] Example 1

[0044] Figure 1 This is a perspective view of the positions of each module of the vibration damping device inside the wind turbine tower of the present invention. (Refer to...) Figure 1 As shown, the vibration reduction device inside the wind turbine tower of the present invention includes an electric drive turntable module 1, a magnetorheological elastomer vibration reduction module 2, and a pressure-magnetic force coordinated stabilization module 3.

[0045] The electric drive turntable module 1 is connected to the top of the wind turbine tower via a rotating shaft and is fixed to two symmetrically distributed magnetorheological elastomer vibration damping modules 2 below via a rigid rod 7. Its function is to ensure that the vibration direction of the magnetorheological elastomer 14 inside the magnetorheological elastomer vibration damping module 2 is always generally consistent with the direction of the external wind. The electric drive turntable module 1 includes a pressure sensor ring 28, an electric drive turntable 6, and a force transmission block 5. The pressure sensor ring 28 is installed on the outside of the wind turbine tower to sense pressure and transmit signals, and the force transmission block 5 is symmetrically installed on both sides of the electric drive turntable 6.

[0046] The magnetorheological elastomer (MEE) vibration damping module 2 is symmetrically distributed below the electric drive turntable 6 and is fixed to the turntable 6 by a rigid rod 7. Its function is to achieve vibration damping by utilizing the variable stiffness and variable damping characteristics of the MEE 14 and the dual-variable intelligent control system of rod adjustment. The MEE vibration damping module 2 includes four MEEs 14, bearings 8, homogeneous light rods 9, electromagnetic plates 12, coils 11, return springs 13, upper telescopic rods 15, lower telescopic rods 16, linkage mechanism 10, telescopic rod base 17, magnetic field shielding layer 18, and magnet blocks 19. Among them, the bearings 8 are placed on the MEE. The top of the variable elastic body vibration damping module 2 is connected to the homogeneous light rod 9. Below the homogeneous light rod 9, four upper telescopic rods 15 are horizontally connected through the linkage mechanism 10. These upper telescopic rods 15 pass through the central rectangular slot of the electromagnetic plate 12 and are inserted into the upper grooves of the four magnetorheological elastic bodies 14. At the same time, the lower telescopic rods 16 connected above the telescopic rod base 17 through the linkage mechanism 10 are inserted into the lower grooves of the magnetorheological elastic bodies 14. The reset spring 13 is sleeved on both ends of the magnetorheological elastic body 14. The electromagnetic plate 12 is wound with a coil 11 and is provided with a magnetic field shielding protection layer 18 and a magnet block 19 on the outside.

[0047] The pressure-magnetic synergistic stabilization module 3 contacts the force transmission block 5 of the electric drive turntable module 1 through the pressure sensor 4. Its function is to realize pressure detection and magnetic synergistic control to maintain system stability. The pressure-magnetic synergistic stabilization module 3 includes a controllable magnetic initiation device 20, a pressure sensor 4, and a control module 21. The pressure sensor 4 is located at the top of the wind turbine tower, the controllable magnetic initiation device 20 is located below the magnetorheological elastomer vibration damping module 2, and the control module 21 is located on the right side of the top of the wind turbine tower and is electrically connected to all sensors, servo electric cylinders, and various encoders.

[0048] In a preferred embodiment, the homogeneous lightweight rod 9 is made of aluminum alloy, with a length of 200 mm, a circular cross-section, and a diameter of 25 mm. The pressure sensor 4 is a piezoelectric force sensor with a range of 0-10 kN. The controllable magnetic initiation device 20 is made of electromagnet, with a maximum attraction force of 1500 N. The magnet block 19 is made of N52 neodymium iron boron permanent magnet, and the magnetic field shielding layer 18 is made of permalloy with a thickness of 10 mm. The magnetorheological elastomer 14 uses methyl vinyl silicone rubber as its matrix material, with hydroxyl iron powder as the particle material, an average particle size of 5 μm, and a volume fraction of 30%. The dimensions of a single magnetorheological elastomer 14 are 240 mm long × 60 mm wide × 80 mm thick, with an elastic modulus of 0.5 MPa under zero field and an elastic modulus of 3.2 MPa under the maximum saturation magnetic field. The electromagnetic plate 12 is made of DT4 electrical pure iron. The dimensions are 250mm long × 250mm wide × 10mm thick. The coil 11 is made of enameled copper wire with 500 turns per coil and a DC resistance of about 2.5Ω. The telescopic rod 15 is made of aluminum alloy with a diameter of 10mm, a length of 250mm, and a maximum stroke of 30mm.

[0049] Example 2

[0050] Figure 2 This is a plan view showing the positions of each module of the vibration damping device inside the wind turbine tower in a preferred embodiment of the present invention. (Refer to...) Figure 2 As shown, the control method of the electric drive turntable module 1 in a preferred embodiment of the present invention is as follows: the electric drive turntable 6 is connected to two magnetorheological elastomer vibration damping modules 2 below it through two symmetrically distributed rigid rods 7; the control module 21 controls the rotation of the electric drive turntable 6 in response to the measurement data of the pressure sensor ring 28.

[0051] In an environment with a specific wind direction, the pressure sensor ring 28 identifies the specific wind direction outside the wind turbine tower and transmits the wind direction identification result to the control module 21. The control module 21 manipulates the electric drive turntable 6 according to the specific wind direction to drive the magnetorheological elastomer 14 inside the magnetorheological elastomer vibration damping module 2 below it to vibrate. The vibration of the wind turbine tower under the specific wind direction will drive the magnetorheological elastomer 14 to undergo shearing motion and generate shearing force. Under the combined action of the electric drive turntable 6 and the swing of the wind turbine tower, the magnetorheological elastomer 14 generates a shearing force opposite to the external wind direction, which cancels out the external wind force, thereby achieving the best vibration damping effect.

[0052] When there is no specific wind direction, the control module 21 manipulates the electric drive turntable 6 to rotate slowly and uniformly, driving the magnetorheological elastomer vibration damping module 2 below to rotate synchronously, so that the magnetorheological elastomer 14 inside the magnetorheological elastomer vibration damping module 2 generates shear force opposite to the direction of various small vibrations of the wind turbine tower, thereby reducing the effect of various small vibrations of the wind turbine tower.

[0053] In a preferred scenario, at an offshore wind farm with a turbine tower height of 90m, a sudden gust of wind shifts from a southeast direction to a direction of 15° south-southeast, accompanied by turbulent fluctuations of ±10°, with a turbulence intensity of approximately 12%. Simultaneously, pressure sensor ring 28 continuously collects the pressure distribution along the circumference of the electric drive turntable 6 at a frequency of 20Hz. At t=0, the ring detects a pressure peak at an azimuth of 135°, consistent with the current orientation of the vibration damping module.

[0054] As the wind direction changes, the pressure sensor ring 28 detects that the pressure peak has shifted to 140° at t=2s, to 148° at t=4s, and to 155° at t=6s. At each moment, the ring transmits the azimuth angle signal corresponding to the pressure peak to the control module 21 in real time.

[0055] At the same time, the annular belt also detected instantaneous pressure fluctuations on both sides of the 155° main peak, and periodic pulsating pressures in the 150° and 160° directions, with amplitudes of about 30% of the main peak, which is a direct manifestation of turbulence.

[0056] After receiving the wind direction signal, control module 21 executes the following decision logic:

[0057] (1) Main wind direction tracking

[0058] Control module 21 performs a moving average filter on the wind direction data over the past 2 seconds to obtain a stable estimate of the prevailing wind direction. At t=4s, the estimated prevailing wind direction is 148°. The control module sends a rotation command to the servo motor of the electric drive turntable 6, driving the turntable to rotate from 135° to 148° at an angular velocity of 5° / s, taking approximately 2.6 seconds. During the rotation, the rigid rod 7 drives the magnetorheological elastomer vibration damping module 2 below to rotate synchronously, ensuring that the swing direction of the homogeneous lightweight rod 9 remains consistent with the real-time prevailing wind direction.

[0059] (2) Periodic reciprocating oscillation to cope with turbulence

[0060] After aligning with the prevailing wind direction, control module 21 did not bring the turntable to a standstill, but instead superimposed a small-range periodic oscillation strategy. Specific parameters are as follows:

[0061] Oscillation center: Current prevailing wind direction 148°

[0062] Swing amplitude: ±8°

[0063] Oscillation period: 3 seconds, corresponding to approximately 0.33 Hz, matching typical turbulence frequencies.

[0064] Motion trajectory: sinusoidal oscillation, i.e.

[0065] This indicates that at t=6s, although the prevailing wind direction has shifted to 155°, the turntable is reciprocating between 140° and 156°. When the actual instantaneous wind direction is 158°, the turntable swings to around 154°, with an angle of only 4° between the two, which is much smaller than the 10° deviation when it is not swinging.

[0066] As the device rotates, it generates an upward centrifugal force. The force transmission block 5 on the drive wheel transmits this pressure to the pressure sensor 4, and the control module 21 then activates the controllable magnetic initiation device 20 below, generating a magnetic force that is equal in magnitude and opposite in direction to the upward force. This magnetic force is used to hold the entire structure in place through the magnet block 19, ensuring smooth operation.

[0067] Once the turntable is aligned, the displacement sensor inside the magnetorheological elastomer damping module 2 detects an increase in the swing amplitude of the homogeneous light rod 9. The system then enters a dual-variable intelligent control process, adjusting the current of the coil 11 to change the stiffness of the magnetorheological elastomer 14, thereby achieving precise matching of the damping force.

[0068] During the oscillation of the turntable, the force transmission block 5 transmits the generated inertial force and upward force to the pressure sensor 4. The pressure-magnetic stabilization module 3 adjusts the output of the controllable magnetic initiation device 20 in real time to ensure that the vibration reduction module remains stable during dynamic movement.

[0069] Example 3

[0070] Figure 3 This is a three-dimensional view showing the detailed internal structure of a magnetorheological elastomer vibration damping module according to a preferred embodiment of the present invention. Figure 4 This is a side view showing the detailed internal structure of the magnetorheological elastomer vibration damping module, referencing... Figure 3 , Figure 4 As shown, the magnetorheological elastomer vibration damping module 2 includes four magnetorheological elastomers 14, an electromagnetic plate 12, a coil 11, a return spring 13, an upper telescopic rod 15, a lower telescopic rod 16, a linkage mechanism 10, a telescopic rod base 17, a magnetic field shielding protective layer 18, and a magnet block 19.

[0071] The bearing 8 is fixed above the top of the magnetorheological elastomer vibration damping module 2, and connected below the bearing 8. The homogeneous light rod 9 is connected below the homogeneous light rod 9. The linkage mechanism 10 is connected below the linkage mechanism 10 through the middle horizontal seam of the electromagnetic plate 12. Finally, the four upper telescopic rods 15 are placed in the four magnetorheological elastomers 14 respectively. The magnetorheological elastomers 14 are placed in the middle of the electromagnetic plate 12.

[0072] When the coil 11 of the electromagnetic plate 12 is energized, a controllable magnetic field is generated. Under the action of the magnetic field, the iron powder in the magnetorheological elastomer 14 will arrange itself into a chain structure along the direction of the magnetic field, so that the elastic modulus of the magnetorheological elastomer will increase synchronously and change continuously and reversibly, thereby realizing wideband adjustment.

[0073] The reset springs 13 on both sides of the magnetorheological elastomer 14 provide initial support for the magnetorheological elastomer 14 and quickly reset the magnetorheological elastomer 14 after vibration to avoid residual deformation. At the same time, the elastic force of the springs and the adjustable stiffness of the magnetorheological elastomer 14 are superimposed to form a dual vibration reduction structure of "basic buffer + dynamic adjustment".

[0074] The upper telescopic rod 15 and the lower telescopic rod 16 are respectively placed in the upper and lower grooves of the magnetorheological elastomer 14. Any pair of upper and lower telescopic rods adopts a simultaneous control scheme. The lower telescopic rod 16 serves to fix the magnetorheological elastomer 14. The upper telescopic rod 15 serves to drive the synchronous movement of each magnetorheological elastomer 14. Specifically, when the upper telescopic rod 15 leaves the upper groove, the lower telescopic rod 16 inserts into the lower groove to fix the magnetorheological elastomer 14. When the lower telescopic rod 16 leaves the lower groove, the upper telescopic rod 15 inserts into the upper groove, which can drive each magnetorheological elastomer 14 to participate in vibration.

[0075] Displacement sensors 22 and velocity sensors 23 are installed on both sides of the magnetorheological elastomer 14; Hall current sensors 26 and temperature sensors 27 are installed near the coil 11; servo electric cylinders 25 are built into the linkage mechanism 10 and the base of the telescopic rod; control modules 21 and acceleration sensors 24 are installed on both sides of the top of the tower; displacement sensors 22, velocity sensors 23, acceleration sensors 24, Hall current sensors 26, temperature sensors 27, and servo electric cylinders 25 are all electrically connected to control module 21; after collecting data from various sensors, control module 21 performs dual-variable intelligent control on the magnitude of the magnetic field of the magnetorheological elastomer 14 and the length of the telescopic rod.

[0076] In a preferred implementation state, the servo electric cylinder 25 has a rated thrust of 1000N, a stroke of 30mm, and a repeatability accuracy of [missing information]. The position encoder located near the servo electric cylinder has a resolution of 0.02mm and a resolution of 0.01mm; the displacement sensor 22 is a laser triangular reflector type with a range of [missing information]. 20, linearity 0.1%FS, speed sensor 23 is a magnetoelectric speed sensor, Hall current sensor 26 has a range of 0-5A DC, and temperature sensor 27 is a PT100 platinum resistance thermometer.

[0077] Example 4

[0078] Figure 5 This is a front view showing the detailed internal structure of the magnetorheological elastomer vibration damping module in a preferred embodiment of the present invention. (Refer to...) Figure 5 The diagram illustrates the detailed structure of the dual control system, which integrates magnetic field adjustment and telescopic rod length adjustment. The practical operation steps of the dual control system for the magnetorheological elastomer vibration damping control module are as follows:

[0079] Step 1: Vibration sensing and spectrum analysis, t=0-0.2s. The system uses the accelerometer 24 above the tower to collect the vibration acceleration at a frequency of 500Hz, obtaining the raw signal a(t). Then, feature extraction is performed. FFT analysis is conducted on the data from the past 2.56 seconds, and the power spectral density S is found to be... aa (f) The dominant vibrational frequency f corresponding to the peak value d It has slowly drifted from 0.6Hz to 0.85Hz; at the same time, frequency band energy analysis shows that the energy proportion of E1 in the 0.5-1.2Hz frequency band is as high as 65%, confirming that the current vibration is dominated by low frequency.

[0080] Step 2: Member state decision and member length optimization, t=0.2-0.5s. First, the control module 21 is used to calculate the natural frequencies and dominant vibration frequencies f of the four magnetorheological elastomers 14. d =0.85Hz deviation Δf i :

[0081] Mode 1, nominal 0.8Hz: Insert groove rod length 30mm, Δf1=0.05Hz;

[0082] Mode 2, nominal 1.4Hz: Inserted groove rod length 0mm, Δf2=0.55Hz;

[0083] Mode 3, nominal 2.1Hz: Inserted groove rod length 0mm, Δf3=1.25Hz;

[0084] Mode 4, nominal 3.2Hz: Inserted groove rod length 0mm, Δf4=2.35Hz

[0085] Based on the data above, we can conclude that Mode 1 has the highest frequency matching degree, and the decision is to "maintain its working state." However, due to the dominant vibration frequency f... d Slightly above the optimal tuning point of Mode 1, the SQP algorithm initiates local optimization, calculating that adjusting the insertion groove rod length of Mode 1 from 30mm to 28mm can raise its natural frequency to approximately 0.86Hz, achieving more precise matching; the optimization objective function minimizes (0.85-f n,1 ) 2 At the same time, it also limits the range of rod length adjustment;

[0086] Step 3: Unified Current Co-optimization, t=0.5-0.6s. The current vibration velocity is obtained through the displacement sensor 22 and velocity sensor 23 on both sides of the magnetorheological elastomer 14, which is used to calculate the desired damping force. At the same time, the strain of each magnetorheological elastomer 14 can also be obtained, with mode 1 being the main mode and other modes approaching 0. The current value of the unified current can be measured by the Hall current sensor 26 as I=1.0A. These data are transmitted to the control module 21, and then the multi-objective grid search and least squares fitting algorithm is started. The grid search is in the range of 0.5A to 2.0A, with a step size of 0.1A, to simulate the output force F of the four magnetorheological elastomers 14 under different currents. i actual and its total error J compared to the expectation vib and energy consumption I 2 R, R is approximately equal to 5Ω;

[0087] Algorithm evaluation revealed that increasing the current from 1.0 A to 1.3 A significantly increased the shear modulus of the magnetorheological elastomer 14 in Mode 1. This provides greater damping force to suppress increased vibration energy while keeping energy consumption within an acceptable range; ultimately, I was determined. opt =1.3A;

[0088] Step 4: Actuator precise tracking control, starting at t=0.6s, the servo electric cylinder 25 in mode 1 receives the command "move to 28mm"; the PID controller in control module 21 starts working, compares the target value with the encoder feedback value, and outputs a control signal; the electric cylinder adjusts the rod length to the position smoothly in about 0.5 seconds to avoid introducing mechanical shock; the current loop PID controller detects that the set value jumps from 1.0A to 1.3A; it quickly increases the PWM duty cycle D(t) to increase the voltage across the coil; in about 0.05 seconds, the Hall sensor feedback current reaches and stabilizes at 1.3A, and the magnetic field strength increases accordingly;

[0089] Step 5: Safety monitoring and parameter self-learning, full process and t=5.0s evaluation. Throughout the process, the system...

[0090] The system monitored the shear strain of magnetorheological elastomer 14 in mode 1. The value never exceeded 0.15, the safety threshold was 0.25, and the coil temperature T slowly rose from 45°C to 48°C, the safety threshold was 80°C, and everything was normal; after one complete vibration cycle after adjustment, the system calculated performance indicators; the root mean square value of the tower top acceleration RMS(a) after control. before The weight is 0.11g, and the vibration reduction efficiency is... ;

[0091] Subsequently, the system records the optimal control combination for this operating condition as: Activation Mode 1, Inserted groove rod length 28mm, Current 1.3A, and stores it in the experience database; if a similar operating condition is encountered again in the future, the system can recall this solution more quickly and achieve a faster response.

[0092] The above description is only a few embodiments of the present invention and is not intended to limit the implementation and protection scope of the present invention. For those skilled in the art, any solutions obtained by making equivalent conversions or obvious changes based on the description and drawings of the present invention shall fall within the protection scope of the present invention.

Claims

1. A semi-active controlled magnetorheological elastomer vibration damping device suitable for wind turbine towers, characterized in that, It includes an electric drive turntable module (1), a magnetorheological elastomer vibration damping module (2), and a pressure-magnetic force co-stabilization module (3). The electric drive turntable module (1) is designed to make the vibration direction of the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration damping module (2) generally consistent with the external wind direction. The electric drive turntable module (1) includes a pressure sensor ring (28), an electric drive turntable (6), and a force transmission block (5). The pressure sensor ring (28) is installed outside the wind turbine tower. The force transmission block (5) is symmetrically arranged above the electric drive turntable (6). Multiple magnetorheological elastomer vibration damping modules (2) are symmetrically distributed and connected below the electric drive turntable (6). The magnetorheological elastomer vibration damping modules (2) are used to achieve the vibration damping effect of the wind turbine tower. The magnetorheological elastomer vibration damping module (2) includes a magnetorheological elastomer (14), a bearing (8), a homogeneous light rod (9), an electromagnetic plate (12), a coil (11) wound on the electromagnetic plate (12), a reset spring (13) sleeved at both horizontal ends of each magnetorheological elastomer (14), an upper telescopic rod (15), a lower telescopic rod (16), a linkage mechanism (10), and a retractable rod. The retractable rod base (17) is provided with a bearing (8) located at the top of the magnetorheological elastomer damping module (2) and connected below a uniform light rod (9). The uniform light rod (9) is connected below a plurality of upper retractable rods (15) via a linkage mechanism (10). The lower ends of the plurality of upper retractable rods (15) pass through an electromagnetic plate (12) and are correspondingly inserted into the upper grooves on the top surfaces of the plurality of magnetorheological elastomers (14). The lower retractable rod (16) connected to the retractable rod base (17) via the linkage mechanism (10) is inserted from below into the lower grooves on the bottom surfaces of the plurality of magnetorheological elastomers (14). The pressure-magnetic synergistic stabilization module (3) includes a controllable magnetic initiation device (20), a pressure sensor (4), and a control module (21). The pressure sensor (4) is located at the top of the vibration damping device and contacts the top of the wind turbine tower. It can sense the upward force generated by the upward movement of the vibration damping device. The controllable magnetic initiation device (20) is located below the magnetorheological elastomer vibration damping module (2) and can generate a magnetic force that balances the upward force. The control module (21) is used to control the operation of each component of the vibration damping device.

2. A semi-active controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, The control method of the electric drive turntable module (1) is as follows: the electric drive turntable (6) is connected to the magnetorheological elastomer vibration damping module (2) below through symmetrically distributed rigid rods (7); the control module (21) controls the rotation of the electric drive turntable (6) in response to the measurement data of the pressure sensor ring (28); In an environment with a specific wind direction, the pressure sensor ring (28) identifies the specific wind direction outside the wind turbine tower and transmits the wind direction identification result to the control module (21). The control module (21) manipulates the electric drive turntable (6) according to the specific wind direction to drive the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration reduction module (2) below it to vibrate. The vibration of the wind turbine tower under the specific wind direction will drive the magnetorheological elastomer (14) to undergo shearing motion and generate shearing force. Under the combined action of the electric drive turntable (6) and the swing of the wind turbine tower, the magnetorheological elastomer (14) generates a shearing force opposite to the external wind direction, which cancels out the external wind force, thereby achieving the best vibration reduction effect. When there is no specific wind direction, the control module (21) manipulates the electric drive turntable (6) to rotate slowly at a uniform speed, which drives the magnetorheological elastomer vibration reduction module (2) below to rotate synchronously, so that the magnetorheological elastomer (14) inside the magnetorheological elastomer vibration reduction module (2) generates shear force opposite to the direction of each small vibration of the wind turbine tower, thereby reducing the effect of each small vibration of the wind turbine tower.

3. A semi-active controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, The core magnetorheological elastomer (14) inside the magnetorheological elastomer vibration damping module (2) is based on silicone rubber and contains carbonyl iron powder with high magnetic permeability. When no magnetic field is applied, the iron powder is randomly distributed and the magnetorheological elastomer is in a flexible state, which can deform freely with vibration.

4. A semi-active controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, When the coil (11) on the electromagnetic plate (12) inside the magnetorheological elastomer damping module (2) is energized, a controllable magnetic field is generated. Under the action of the magnetic field, the iron powder in the magnetorheological elastomer (14) is arranged into a chain structure along the direction of the magnetic field, so that the elastic modulus of the magnetorheological elastomer is synchronously increased and the change is continuous and reversible, thereby realizing wide frequency adjustment. The reset spring (13) inside the magnetorheological elastomer vibration damping module (2) provides initial support for the magnetorheological elastomer (14) on the one hand, and helps the magnetorheological elastomer (14) to quickly reset after vibration, avoiding residual deformation. At the same time, the elastic force of the spring and the adjustable stiffness of the magnetorheological elastomer (14) under the magnetic field are superimposed to form a dual vibration damping structure of "basic buffer + dynamic adjustment".

5. A semi-actively controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, The upper telescopic rod (15) and lower telescopic rod (16) inside the magnetorheological elastomer vibration damping module (2) are respectively placed in the upper and lower grooves of the magnetorheological elastomer (14). Any set of upper and lower telescopic rods adopts a simultaneous control scheme. The lower telescopic rod (16) serves to fix the magnetorheological elastomer (14). The upper telescopic rod (15) serves to drive each magnetorheological elastomer (14) to move synchronously. The specific control scheme is as follows: when the upper telescopic rod (15) leaves the upper groove, the lower telescopic rod (16) inserts into the lower groove, thereby fixing the magnetorheological elastomer (14); when the lower telescopic rod (16) leaves the lower groove, the upper telescopic rod (15) inserts into the upper groove, thereby driving each magnetorheological elastomer (14) to participate in vibration.

6. A semi-actively controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 4, characterized in that, The upper telescopic rod (15) and lower telescopic rod (16) of the magnetorheological elastomer vibration damping module (2) are connected by a linkage mechanism (10) to achieve synchronous movement; the linkage mechanism (10) is equipped with a servo electric cylinder (25), and the rod position encoder is built into the servo electric cylinder (25); the servo electric cylinder (25) can be controlled by the control module (21) to form a dual control of the stiffness adjustment of the magnetorheological elastomer (14) and the telescopic rod adjustment, so as to realize the precise wideband adjustment of the magnetorheological elastomer (14); the telescopic rod includes an upper telescopic rod (15) and a lower telescopic rod (16).

7. A semi-actively controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, The magnetorheological elastomer (14) is provided with a displacement sensor (22) and a velocity sensor (23) on both sides, an acceleration sensor (24) is provided at the top of the wind turbine tower, and a Hall current sensor (26) and a temperature sensor (27) are provided near the coil (11); the displacement sensor (22), velocity sensor (23), acceleration sensor (24), servo motor (24), Hall current sensor (26) and temperature sensor (27) are all electrically connected to the control module (21).

8. A semi-active controlled magnetorheological elastomer vibration damping device for wind turbine towers according to claim 1, characterized in that, A magnetic field shielding protective layer (18) and a magnet block (19) are arranged sequentially on the lower part of the outside of the magnetorheological elastomer vibration damping module (2). The application scenario and working mode of the pressure-magnetic synergistic stabilization module (3) are as follows: When the electric drive turntable (6) drives the magnetorheological elastomer vibration damping module (2) below to rotate, it will generate an upward force. The force transmission block (5) on the electric drive turntable (6) can transmit the generated upward force to the pressure sensor (4) above the tower. After being subjected to force, the pressure sensor (4) will transmit the pressure magnitude signal to the control module (21). The control module (21) controls the controllable magnetic initiation device (20) below the magnetorheological elastomer vibration damping module (2) to generate a corresponding magnetic force, which is transmitted to the device above through the magnet block (19) to make it operate safely and stably. In order to prevent the controllable magnetic initiation device (20) from affecting the magnetic field in the magnetorheological elastomer vibration damping module (2), a magnetic field shielding protection layer (18) is set between the magnetorheological elastomer vibration damping module (2) and the magnet block (19).

9. A control method for achieving vibration reduction of wind turbine towers using a semi-active control magnetorheological elastomer vibration damping device suitable for wind turbine towers as described in any one of claims 1-8, characterized in that, The magnetorheological elastomer (14) inside the magnetorheological elastomer vibration damping module (2) is subjected to dual control of stiffness adjustment and telescopic rod adjustment, including the following steps, wherein the telescopic rod includes an upper telescopic rod (15) and a lower telescopic rod (16): Step 1: Vibration sensing and spectrum analysis. The real-time FFT algorithm is used to collect the tower vibration acceleration time domain signal through the accelerometer (24) at the rated sampling frequency. After windowing filtering preprocessing, the FFT is converted to the frequency domain to obtain the complex spectrum, and the power spectral density is calculated. The frequency corresponding to the maximum power spectral density in the range of 0.2-5.0Hz is extracted as the dominant vibration frequency. The spectrum is divided into three frequency bands to calculate the vibration energy. Step 2: State decision-making and rod length optimization of the telescopic rod. Based on the frequency matching heuristic rule and the sequential quadratic programming (SQP) algorithm, the system calculates the equivalent natural frequency f of each magnetorheological elastomer (14). n,i ; Calculate the natural frequency f n,i With the current dominant vibration frequency f d deviation The unit with the smallest deviation is activated first; the optimal rod length is determined by a weighted combination of minimizing the sum of squares of frequency matching deviation and the sum of squares of rod movement amplitude. The optimization process is constrained by the mechanical stroke of the telescopic rod. Step 3: Unified Current Cooperative Optimization, using multi-objective grid search and least squares fitting to optimize the unified coil current I. opt Minimize the difference between the actual damping force and the desired force, as well as the energy consumption I. 2 R, where R is the coil resistance; the output force F of each magnetorheological elastic body (14) is calculated. i actual By adjusting the multi-objective weighting coefficients α and β, a trade-off is struck between vibration reduction effect and energy consumption, and the globally optimal damping force is output. Step 4: The control module (21) performs precise tracking control, which includes two parallel closed loops: the position of the lever adopts a PID position servo algorithm; the control module (21) receives the target lever length L. i target and the actual rod length L fed back by the encoder. i target (t) Comparison yields the position tracking error e i (t); Output control signal u to drive the servo electric cylinder i (t), ensuring precise movement of the linkages and compliance with mechanical interlocking logic; The current control employs a PWM closed-loop regulation algorithm to optimize the target current I. opt To set the value, the actual current I in the coil is measured in real time using a Hall current sensor (26). actual By adjusting the duty cycle of the pulse width modulation signal, rapid and error-free tracking of the coil current is achieved, and the required magnetic field strength is accurately generated.

10. The application of a semi-active control magnetorheological elastomer vibration damping device for wind turbine towers according to any one of claims 1-8 or the control method according to claim 9 in vibration damping of wind turbine towers.

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